[Sudden death in acute pulmonary embolism]

A current problem associated with pulmonary thromboembolism is the absence of a decrease in the mortality rate, which seems due to overlooking of the disease and subsequent sudden death. This study tried to find methods to decrease the mortality rate through a clinical investigation of sudden death. Of 162 patients, 44 suffered sudden death (within 24 hours of onset). Among these, 28 patients died within 1 hour and 9 within 1 to 24 hours. In the remaining seven patients, the time until death could not be determined because the subject was detected postmortem. Pathological examination revealed occlusion of the pulmonary trunk or the bilateral pulmonary arteries in 58% (23/40). All patients who did not receive adequate cardiopulmonary resuscitation suffered occlusion at these sites. Occlusion of one of the pulmonary arteries or of the peripheral arteries alone was found in 42% (17/40) and all these patients received adequate cardiopulmonary resuscitation. In addition, the incidence of cardiopulmonary disease was 56% in this group, which was higher than the rate of 35% for the group with central occlusion. Of the nine patients with sudden death after 1 to 24 hours, five died at 5 or more hours after the onset and none had been examined by a physician. Among patients dying within 1 hour, 60% of those with onset outside hospital had preexisting symptoms, suggesting sudden death can be avoided by educating the general population about the major symptoms. In contrast, the frequency of preexisting symptoms in the inpatients was low. As it is difficult to differentiate preexisting symptoms from symptoms caused by the underlying disease, it may be impossible to predict sudden death due to acute pulmonary thromboembolism. Therefore, better measures to prevent deep vein thrombosis are required.